Tripoli , Libya -LRB- CNN -RRB- -- Libyan authorities have made more arrests in connection with the attack on the U.S. Consulate that left the U.S. ambassador and three others dead , the president of Libya 's parliament said Sunday .

Mohamed al-Magariaf , the head of Libya 's General National Congress , said around 50 people have been arrested , though another senior government official said the number was not that high .

The official said as many as 50 people have been brought in for questioning but not all of them were arrested . They were people who were at a protest outside the consulate but there was no indication yet that they took part in the violence , he said .

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Al-Magariaf told CBS ' `` Face the Nation '' that a `` few '' of those arrested are foreigners , some of them from Mali and Algeria . The others are affiliated with al Qaeda or are sympathizers , he said .

Al-Magariaf said he has `` no doubt '' the fatal attack was planned and not a result of the anti-American demonstrations that began that day -- the 11th anniversary of the September 11 , 2001 , terrorist attacks on the United States .

`` Definitely it was planned by foreigners , by people who entered the country a few months ago , and they were planning this criminal act since their arrival , '' he said .

The senior Libyan government official said there is no evidence yet that the attack was planned or that al Qaeda was involved .

U.S. officials believe extremists carried out the attack on the consulate in Benghazi , but that they did it after a spontaneous protest began outside the building , said Susan Rice , the U.S. ambassador to the United Nations .

`` We do not have information at present that leads us to conclude that this was premeditated or preplanned , '' Rice told `` Face the Nation . ''

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The FBI is investigating the attack but has yet to enter the country because of volatility there . In the meantime , FBI agents are interviewing witnesses outside Libya , federal law enforcement officials said .

The United States has , however , deployed warships and surveillance drones in its hunt for the killers , and a contingent of 50 Marines has arrived to boost the security of Americans in Libya .

Militants stormed the consulate in Benghazi on Tuesday , killing Ambassador Christopher Stevens and three other Americans .

The protest in front of the consulate was over a film , made in the United States , that mocks the Prophet Mohammed .

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CNN 's Jomana Karadsheh contributed to this report .

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The president of Libya 's parliament says around 50 people are arrested

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Another senior official disputes that number and says 50 have been questioned

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There are differing views on whether the Tuesday attack was planned